Dynamically retrieve key's value from a terraform yaml file - terraform

Question

I am trying to get a value from a key in a yaml file after decoding it in locals:
document.yaml
name: RandomName
emailContact: email#domain.com
tags:
- key: "BusinessUnit"
value: "BUnit"
- key: "Criticality"
value: "Criticality-Eng"
- key: "OpsCommitment"
value: "OpsCommitment-Eng"
- key: "OpsTeam"
value: "OpsTeam-Eng"
- key: "BudgetAmount"
value: "100"
Then I have locals in main.tf:
locals {
file = yamldecode(file(document.yaml))
}
And a have a budget.tf file where I need to retrieve the BudgetAmount of 100 dollars based on the tag key: BudgetAmount
resource "azurerm_consumption_budget_subscription" "budget" {
name = format("%s_%s", lower(var.subscription_name), "budget")
subscription_id = data.azurerm_subscription.current.id
amount = local.landing_zone.tags[5].value
time_grain = "Monthly"
time_period {
start_date = formatdate("YYYY-MM-01'T'00:00:00'Z'", timestamp())
end_date = local.future_10_years
}
notification {
enabled = true
threshold = 80.0
operator = "EqualTo"
contact_emails = [
]
contact_roles = [
"Owner"
]
}
}
This local.landing_zone.tags[5].value works, but it's not a good idea if I have multiple yaml files and the position changes
Q: how do I get the BudgetAmount value of 100 from the yaml file without specifying its location inside the file, but referring to the tag's name?
I did try this:
matchkeys([local.file .tags[*].key], [local.file .tags[*].value], ["BudgetAmount"])
but it keeps telling me the value needs to be a number (obviously is getting a value, but it's a text, from one of the many key/value pairs I have in the yaml file)

Answer 1

I managed to get the budget by converting the list of maps into a single map with each tag being a key value.
The way you were doing it would result in the following data structure under local.file.tags:
[
{
"key" = "BusinessUnit"
"value" = "BUnit"
},
{
"key" = "Criticality"
"value" = "Criticality-Eng"
},
{
"key" = "OpsCommitment"
"value" = "OpsCommitment-Eng"
},
{
"key" = "OpsTeam"
"value" = "OpsTeam-Eng"
},
{
"key" = "BudgetAmount"
"value" = "100"
},
]
That was hard to work with and I couldn't think of any functions to help at the time so I went with changing it via the following locals:
locals {
file = yamldecode(file("document.yaml"))
tags = {
for tag in local.file.tags :
tag.key => tag.value
}
}
which got the tags to a structure of:
> local.tags
{
"BudgetAmount" = "100"
"BusinessUnit" = "BUnit"
"Criticality" = "Criticality-Eng"
"OpsCommitment" = "OpsCommitment-Eng"
"OpsTeam" = "OpsTeam-Eng"
}
You can reference each of the tags in this state by using something like:
budget = local.tags["BudgetAmount"]
This was tested on Terraform v1.0.10 via terraform console